Role of ethanol in improvement of bacterial cellulose production:: Analysis using 13C-labeled carbon sources

We studied the role of ethanol in the improvement of bacterial cellulose (BC) production, primarily using C-13 NMR. C-13-labeled BC was biosynthesized by Acetobacter xylinum ATCC 10245 using culture media containing D-(1-C-13), (2-C-13), and (6-C-13)glucose. The introduction of (1-C-13) ethanol was also investigated. Ethanol was not utilized as a carbon source for BC production, but was oxidized to acetic acid. The consumption rate of glucose and the extracellular conversion of glucose into gluconic acids were suppressed by the ethanol supplementation. The direct polymerization of the glucose into BC was accelerated; in contrast, the participation of the Entener-Doudoroff pathway was reduced by the ethanol supplementation. These results support the hypothesis that the improvement of BC production by ethanol supplementation can be achieved by the effective use of glucose. Ethanol could be used as a substitute for glucose and gluconic acids, and a source for metabolites in the tricarboxylic acid cycle.